title: Chitosan/polyaniline hybrid conducting biopolymer base impedimetric immunosensor to detect Ochratoxin-A.
abstract: Chitosan (CS)-polyaniline (PANI) hybrid conducting biopolymer film was obtained on indium-tin-oxide (ITO) electrode using electrochemical polymerization process. Fourier transform infrared (FT-IR) spectra of PANI-CS had showed covalent and hydrogen binding between PANI and CS molecules. Electrochemical impedance spectroscopy (EIS) measurements had showed low charge transfer resistance (R(CT)) of PANI-CS and PANI. Successive rabbit antibody (IgGs) immobilization on PANI-CS, CS and PANI matrixes surface were confirmed with FT-IR and EIS measurements. Ochratoxin-A (OTA) interaction with IgGs had increased R(CT) values and showed linear response up to 10 ng/mL OTA concentration in electrolyte. Relative change in R(CT) was higher in PANI-CS due to higher proportion of carboxylic and hydroxyl functionalities at PANI-CS matrix surfaces. The absolute sensitivity of PANI, CS, and PANI-CS were 16+/-6, 22+/-9 and 53+/-8 Omega mL/ng, respectively derived from slope of linear response up to 10 ng/mL with 1 ng/mL minimum detection limit.
authors.affiliation: Analytical Chemistry, North East Institute of Science & Technology, Jorhat, Assam, India.
authors.forename: Raju
authors.initials: R
authors.lastname: Khan
authors.forename: Marshal
authors.initials: M
authors.lastname: Dhayal
mesh_terms: D000814:Aniline Compounds / Q000737:chemistry*; D001672:Biocompatible Materials / Q000737:chemistry*; D015374:Biosensing Techniques / Q000295:instrumentation* / Q000379:methods; D048271:Chitosan / Q000737:chemistry*; D004553:Electric Conductivity; D017097:Electric Impedance; D004563:Electrochemistry / Q000295:instrumentation*; D004566:Electrodes; D004867:Equipment Design; D019544:Equipment Failure Analysis; D005504:Food Analysis / Q000295:instrumentation* / Q000379:methods; D005506:Food Contamination / Q000032:analysis*; D007118:Immunoassay / Q000295:instrumentation* / Q000379:methods; D009793:Ochratoxins / Q000032:analysis*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity
chemical_list: D000814:Aniline Compounds; D001672:Biocompatible Materials; D009793:Ochratoxins; C416807:polyaniline; C025589:ochratoxin A; D048271:Chitosan